linux/arch/frv/mb93090-mb00/pci-dma.c
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   1/* pci-dma.c: Dynamic DMA mapping support for the FRV CPUs that have MMUs
   2 *
   3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version
   9 * 2 of the License, or (at your option) any later version.
  10 */
  11
  12#include <linux/types.h>
  13#include <linux/slab.h>
  14#include <linux/dma-mapping.h>
  15#include <linux/list.h>
  16#include <linux/pci.h>
  17#include <linux/highmem.h>
  18#include <linux/scatterlist.h>
  19#include <asm/io.h>
  20
  21void *dma_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t gfp)
  22{
  23        void *ret;
  24
  25        ret = consistent_alloc(gfp, size, dma_handle);
  26        if (ret)
  27                memset(ret, 0, size);
  28
  29        return ret;
  30}
  31
  32EXPORT_SYMBOL(dma_alloc_coherent);
  33
  34void dma_free_coherent(struct device *hwdev, size_t size, void *vaddr, dma_addr_t dma_handle)
  35{
  36        consistent_free(vaddr);
  37}
  38
  39EXPORT_SYMBOL(dma_free_coherent);
  40
  41/*
  42 * Map a single buffer of the indicated size for DMA in streaming mode.
  43 * The 32-bit bus address to use is returned.
  44 *
  45 * Once the device is given the dma address, the device owns this memory
  46 * until either pci_unmap_single or pci_dma_sync_single is performed.
  47 */
  48dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
  49                          enum dma_data_direction direction)
  50{
  51        if (direction == DMA_NONE)
  52                BUG();
  53
  54        frv_cache_wback_inv((unsigned long) ptr, (unsigned long) ptr + size);
  55
  56        return virt_to_bus(ptr);
  57}
  58
  59EXPORT_SYMBOL(dma_map_single);
  60
  61/*
  62 * Map a set of buffers described by scatterlist in streaming
  63 * mode for DMA.  This is the scather-gather version of the
  64 * above dma_map_single interface.  Here the scatter gather list
  65 * elements are each tagged with the appropriate dma address
  66 * and length.  They are obtained via sg_dma_{address,length}(SG).
  67 *
  68 * NOTE: An implementation may be able to use a smaller number of
  69 *       DMA address/length pairs than there are SG table elements.
  70 *       (for example via virtual mapping capabilities)
  71 *       The routine returns the number of addr/length pairs actually
  72 *       used, at most nents.
  73 *
  74 * Device ownership issues as mentioned above for dma_map_single are
  75 * the same here.
  76 */
  77int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
  78               enum dma_data_direction direction)
  79{
  80        unsigned long dampr2;
  81        void *vaddr;
  82        int i;
  83
  84        if (direction == DMA_NONE)
  85                BUG();
  86
  87        dampr2 = __get_DAMPR(2);
  88
  89        for (i = 0; i < nents; i++) {
  90                vaddr = kmap_atomic(sg_page(&sg[i]), __KM_CACHE);
  91
  92                frv_dcache_writeback((unsigned long) vaddr,
  93                                     (unsigned long) vaddr + PAGE_SIZE);
  94
  95        }
  96
  97        kunmap_atomic(vaddr, __KM_CACHE);
  98        if (dampr2) {
  99                __set_DAMPR(2, dampr2);
 100                __set_IAMPR(2, dampr2);
 101        }
 102
 103        return nents;
 104}
 105
 106EXPORT_SYMBOL(dma_map_sg);
 107
 108/*
 109 * Map a single page of the indicated size for DMA in streaming mode.
 110 * The 32-bit bus address to use is returned.
 111 *
 112 * Device ownership issues as mentioned above for dma_map_single are
 113 * the same here.
 114 */
 115dma_addr_t dma_map_page(struct device *dev, struct page *page, unsigned long offset,
 116                        size_t size, enum dma_data_direction direction)
 117{
 118        BUG_ON(direction == DMA_NONE);
 119        flush_dcache_page(page);
 120        return (dma_addr_t) page_to_phys(page) + offset;
 121}
 122
 123EXPORT_SYMBOL(dma_map_page);
 124